In construction, sand, gravel, mixtures of same and other coarse particulate materials (generally referred to as “aggregate”) are used as base material (at times herein referred to as “soil”) to provide a stable foundation for an overlying feature, for example a concrete feature (e.g., a footing or slab), pavers etc.
When used, base material is generally compacted so as to reduce later settling/subsidence. It is also generally desirable to make the top surface of the base material flat and/or level, for example so as to be parallel to the top surface of a planar overlying feature. For example, a poured concrete slab gains strength and integrity from being uniform in thickness. To achieve this in the case of a slab poured on ground, the top of the base material must be made parallel to the planned top surface of the concrete slab. As well, making the ground parallel to the planned top surface of a concrete slab optimizes (in terms of cost) the amount of concrete used to make the slab.
Vibratory plate compactors are often used to compact base material. A vibratory plate compactor has a vibratory plate, an exciter component, a spring decoupling component and an upper mass comprising a motor (e.g. internal combustion engine) as a source of power to drive the exciter component, a cover and a structural frame. The exciter component is connected between the vibratory plate and the drive output of the motor, and the spring decoupling component is connected between the vibratory plate and the upper mass to permit the vibratory plate to vibrate relative to the upper mass. Typically, a plate compactor is configured such that the vibration tends to propel, or to assist in propelling, the compactor in a forward direction, while permitting the operator to move the plate compactor in the reverse direction or in other directions (e.g., side to side).
In many construction situations, when it is desirable to make the top surface of the base material flat and/or level, the ground is initially made roughly level/flat through the use of larger construction equipment. In most cases, the leveling achieved thereby is inadequate as there remain high and low spots that deviate from the desired plane.
Thus, when using a vibratory plate compactor to compact base material, it is usually necessary to hand level the base material, for example by using a landscaping rake or other such implement to remove base material from areas higher than the desired plane and apply base material to other areas lower than the desired plane. This is generally accomplished with a second worker while the compaction operation takes place.
The iterative process of compacting and leveling is time consuming because it requires repeated passes of compaction each time base material is moved from one location to another. It is also labour-intensive because the raking process generally involves removing base material from a high spot that has already been compacted.